These comms were recorded on 235.250 MHz, Thunderbird Control frequency. You'll be able to hear the pilot of Thunderbird 7 located somewhere at the track talking to Thunderbird 1 in order to get the timing of the flyover perfect. You'll hear him say "we're 4 seconds early" meaning the person singing the National Anthem was going to finish 4 seconds early, and of course the Thunderbirds made the adjustment....just amazing!